胶原蛋白-壳聚糖膜的制备及其对猪肉的保鲜作用

为了延缓猪肉的腐坏变质,延长猪肉的保质期,保持猪肉良好的品质,本文研究了没食子酸(GA)改性超声辅助制备的胶原蛋白-壳聚糖复合膜对冷藏猪肉的保鲜效果。在4℃冷藏条件下,采用未经过膜包裹(对照组)和GA改性超声膜包裹(膜包裹组)2种方式处理猪肉样品,并贮藏10d,检测其p H值、挥发性盐基氮(TVB-N)值、细菌总数、质构、色差ΔE值,以及感官质量。结果表明,对照组和膜包裹组猪肉的p H值、TVB-N、细菌总数、色差ΔE均随着贮存时间的增加而上升,但是膜包裹组的数值比对照组分别低了8.39%、26.18%、17.54%和8.23%,得出膜包裹处理可以显著降低碱性含氮物质和细菌产生的数量以及减缓颜色的变差(p<0.05)。对照组和膜包裹组猪肉的硬度、弹性和感官指标均随着贮存时间的增加而下降,但是膜包裹组的数值比对照组分别高了80.01%、18.66%和160.38%,得出膜包裹处理可以显著改善猪肉的质构和感官指标(p<0.05)。由此说明,膜包裹处理可以通过抑制p H值、TVB-N和细菌总数的增高,有效延缓猪肉的腐坏变质,延长猪肉的保质期。而且,经膜包裹处理10d后的猪肉仍然具有良好的质构、颜色和感官品质。

Preparation of Collagen-chitosan Film and its Preservation of Pork

In order to delay the decay and deterioration of pork, extend the shelf life of pork and maintain the good quality of pork, the effects of collagen-chitosan composite film modified by ultrasound and gallic acid(GA) on pork preservation were studied. Under the condition of 4 ℃ r efrigeration, the pork samples were treated by two methods: without film packaging(control group) and GA modified ultrasonic film packaging(film packaged group), and stored for 10 d. The pH, total volatile base nitrogen(TVB-N), total bacteria count, texture, ΔE value and sensory quality were taken as the study indexes. The results showed that in the control and film packaged groups, the pH, TVB-N, total bacteria count, and ΔE values were all increased with the increase of storage time. The values of film packaged group was 8.39%, 26.18%, 17.54%, and 8.23% respectively, which were lower than those of the control group. It indicated that film packaging treatment can significantly reduce the amount of alkaline nitrogen containing substances and bacteria production, and slow down the deterioration of color(p<0.05). The hardness, elasticity, and sensory evaluation values of pork in the control and film packaged groups all showed the decreasing trend with the increase of storage time. The values of film packaged group were 80.01%, 18.66%, and 160.38% respectively, which were higher than those of the control group. It indicated that film packaging treatment can significantly improve the texture and sensory indicators of pork(p<0.05). In general, it was concluded that compared to the control, film packaging treatment can effectively delay the decay and deterioration, and was helpful to extend the shelf life of pork by inhibiting the increases of pH, TVB-N and total bacteria count. After 10 days of film packaging treatment, the pork still maintains the good texture, color, and sensory quality.